NEW YORK - Amid continuing Delhi-Washington standoff over the arrest of a female Indian diplomat, a New York-based Sikh advocacy group on Sunday came out in support of the US move to prosecute her on charges of visa fraud and underpaying her maid.

Devyani Khobragade, 39, India's deputy consul general, who was handcuffed and strip-searched while in detention, has denied the charges and in turn accused her maid, Sangeeta Richard, of theft and attempted blackmail.

“Ms Khobragade should be tried in the US Court as, we are in a country where law of land is supreme and immunity to anyone based on their official position is unacceptable”, Gurpatwant Singh Pannun, the legal advisor to the group, "Sikhs for Justice, said in a statement.

In calling for the Indian diplomat’s prosecution, Pannun welcomed the 2013 report of the UN Special Rapporteur on extrajudicial, summary or arbitrary executions, Christof Heyns, which says that impunity represents a major challenge in India. Heyns, who visited India in 2012, presented the report to UN Human Rights Council (UN HRC), recommending ‘a series of legal reforms and policy measures aimed at fighting impunity and decreasing the level of unlawful killings in India”.

In his statement, Pannun said that Prime Minister Manmohan Singh, who continues to provide impunity in India to its cabinet members like Kamal Nath and other leaders for their alleged involvement in November 1984 anti-Sikh riots, was now demanding immunity for Khobragade from US government. India has demanded an apology from the US over the diplomat's alleged "humiliation".

Khobragade has since been posted to India's Mission to the United Nations in New York in a move to give her full diplomatic immunity from prosecution.

American officials so far insist that whatever immunity Ms Khobragade earns from the switch will not be retroactive.

“Receiving diplomatic immunity does not nullify any previously existing criminal charges,” said Jen Psaki, the State Department spokeswoman. “Those remain on the books.”  Meanwhile, India is checking the tax status of Americans working at schools in the country, after the arrest this month of an Indian diplomat in New York, according to US media reports.

In a dispatch from New Delhi, The New York Times said Indian Foreign Service officials are not letting the matter drop even though politicians have stopped denouncing the United States for the arrest and humiliation of Ms Khobragade. "The continued hard feelings suggest that the dispute could have a long-term impact on a relationship both sides say is crucial," the report said. India would no longer turn a blind eye to tax violations by diplomats' spouses taking up work in the country, an unnamed official was quoted as saying in media reports.

New Delhi has also withdrawn some privileges enjoyed by American diplomats and their families in the country, added the official. "Spouses and children have no more immunity. So if there is a parking offence or something else happening in Bangalore etcetera, they would be held liable."

India has also canceled the United States Embassy’s import privileges for food and alcohol, according to The New York Times. And security barriers that surrounded the embassy in New Delhi have been permanently removed.  Indian officials say the barriers were unnecessary and in some cases impeded traffic.

“We would not do anything to adversely affect the security of the US Embassy,” the Indian External Affairs Ministry spokesman was quoted as saying. “To suggest otherwise is unfair.”

There are 14 other Indian maids working for Indian diplomats in the United States, and India is negotiating over their status with the State Department, it said. To India, these maids should be considered Indian government employees whose employment does not fall under American wage and hour laws. The US embassy declined to comment on the latest steps.

The New York Times dispatch said, "A little-noticed aspect of the uproar has been India’s unhappiness with American officials of Indian descent. The federal prosecutor on the case, Preet Bharara, is of Indian descent, as are many officials on the South Asia desk of the United States State Department.

"India has a fraught relationship with members of its own diaspora. Commercials and Bollywood films often treat such people with mild contempt, and in the Khobragade case, Indian officials have said they believe that their counterparts in the United States treated India poorly in an excessive show of loyalty to the United States.

"American officials quietly say they bent over backward to heal bruised feelings. On Dec. 19, Secretary of State John Kerry tried to get in touch with the Indian foreign secretary, Salman Khurshid, but Khurshid did not take his call for reasons he has not explained. So Kerry called Shivshankar Menon, the Indian national security adviser, to express his “regret” over the matter.

"While US Secretary of State John Kerry has expressed his "regret" over Ms Khobragade's arrest, the state department has said it will not drop charges, as requested by India."

The Times said, "Ms. Khobragade could leave the United States for India, never return and never face another day in court, but that seems unlikely because her husband, a professor of philosophy, was raised in the United States and has family there."